Year % of GNI 2008 3.74726482705054 2009 4.55358863336495 2010 4.58608770373303 2011 3.94841518957112 2012 3.96249242370555 2013 3.88560522902805 2014 3.4516805511206 2015 4.68486361896818 2016 4.83122112124034 2017 4.16364998820138 2018 4.03934982352925 2019 4.34518019089588 2020 4.65249026879713 2021 4.19021680239907